Multimer forms of mono-and bis-acylphosphine oxides

ABSTRACT

The invention relates to dimer and multimer form of BAPO compounds of the formula (I) dimer and multimer forms of MAPO compounds of the formula (II) wherein R 1 , R 2 , and R 3  independently of one another are unsubstituted or substituted C 1 –C 12 alkyl, benzyl, C 1 –C 12 alkoxy, C 3 –C 6 cycloalkyl or C 5 –C 14 aryl; Q is a di- tri or tetravalent arylene residue; n is 1–4, m is 0–2, n+m is 2, 3 or 4, with the proviso, that R 1  and R 3  are different from each other. The invention further relates to a process for the preparation of dimer or multimer forms of BAPO compounds of the formula (I) and of dimer or multimer forms of MAPO compounds of the formula (II), characterized in the (n+m) equivalents of a dimetalated-phosphine R 1 P(M) 2  is reacted with one equivalent of a di- or polycarboxylic acid halogenide to form an intermediate of the formula III the intermediate is then reacted either with (n+m) equivalents of a further carboxylic acid halogenide (R 2 —CO-Hal) or with a halogenide R 3 -Hal, the reaction products are then oxidized to form phosphine oxides of the formula I or II

The present invention relates to new dimer and multimer forms ofmonoacylphosphine oxides (MAPO), bisacylphosphine oxides (BAPO), to newcyclic forms of bisacyl phosphine oxides (BAPO), to a process for theirpreparation and to new acylphosphine compounds obtained as intermediatesin said process.

The preparation of dimer forms of monoacylphosphine oxides of thegeneral formula

has been described in the European Patent Publication EP-A 0 601 413.Said process is characterized in that an arene-bisacyl chloride isreacted with e.g. an alkoxy-diphenyl-phosphine. The compounds obtainedare due to the alkoxy-diphenylphosphine reactant symmetric dimer formsof monoacylphosphine oxides, i.e. the residue R₅═R₆. Concerningasymmetric forms one of the residues R₅ or R₆ must be an alkoxy group.

The U.S. Patent Publication 2001/0031898 describes the preparation ofmonomer forms of bisacylphosphine oxides

by reacting an acyl halide Ar—CO—X with a dimetalated phosphine RP(M)₂and subsequent reaction of the product obtained with an acyl halide.Dimer forms of BAPO compounds are encompassed by the general definitionof the compounds described in U.S. Patent Publication 2001/0031898 butthey have not been actually and explicitly disclosed in this patentpublication, nor the preparation thereof has been exemplified.

There is still a need to find a method for preparing both, dimer andmultimer symmetric and asymmetric forms of BAPO and MAPO compounds aswell as cyclic forms of BAPO compounds, whereby said method should, incase of MAPO compounds, have a broad latitude in the choice ofsubstituents on the phosphor atom.

In one aspect the invention relates to dimer and multimer forms of BAPOcompounds of the formula I

wherein

-   R₁ is unsubstituted or substituted C₁–C₁₂alkyl, benzyl,    C₁–C₁₂alkoxy, C₃–C₆cycloalkyl or C₅–C₁₄aryl;-   R₂ is unsubstituted or substituted C₃–C₆cycloalkyl or C₅–C₁₄aryl;-   Q is a di-tri or tetravalent arylene residue;-   n is 1–4, m is 0–2, n+m is 2, 3 or 4.

The invention further relates to dimer and multimer forms of MAPOcompounds of the formula II

wherein

-   R₁ and R₃ independently of one another are unsubstituted or    substituted C₁–C₁₂alkyl, benzyl, C₁–C₁₂alkoxy, C₃–C₆cycloalkyl or    C₅–C₁₄aryl;-   Q is a di-tri or tetravalent arylene residue;-   n is 1–4, m is 0–2, n+m is 2, 3 or 4;-   with the proviso, that R₁ and R₃ are different from each other.

The invention further relates to a process for the preparation of dimeror multimer forms of BAPO compounds of the formula I and of dimer ormultimer forms of MAPO compounds of the formula II,

characterized in that (n+m) equivalents of a dimetalated-phosphineR₁P(M)₂ are reacted with one equivalent of a di- or polycarboxylic acidhalogenide

to form an intermediate of the formula III

the intermediate is then reacted either with (n+m) equivalents of afurther carboxylic acid halogenide (R₂—CO-Hal) to form dimer or multimerforms of bisacylphosphine-intermediates of the formula IV

or with a halogenide R₃-Hal to form dimer or multimer forms ofmonoacylphosphine intermediates of the formula V

said phosphines IV or V are then oxidized to form phosphine oxides ofthe formula I or II, wherein M is Li, Na or K and R₁, R₂ and R₃; Q, nand m are as defined above.

The intermediate compounds of the formula III are novel and are alsopart of the invention. Thus, the invention further relates to compoundsof the formula III as defined above. The compounds of the formula IIIare identified by ³¹P-.NMR spectroscopy and are stable in solution underinert gas at room temperature for a number of weeks.

The invention further relates to cyclic forms of BAPO compounds of theformula VI and VII

wherein

-   R₁ is unsubstituted or substituted C₁–C₁₂alkyl, benzyl,    C₁–C₁₂alkoxy, C₃–C₆cycloalkyl or C₅–C₁₄aryl;-   U is a divalent arylene residue and U′ is a tetravalent arylene    residue.

The invention further relates to a process for the preparation of cyclicforms of BAPO compounds of the formula VI

characterized in that one equivalent of a dimetalated-phosphine R₁P(M)₂is reacted with one equivalent of a dicarboxylic acid halogenide

to form an intermediate of the formula III′

said intermediate cyclizes and is then oxidized to form phosphine oxidesof the formula VI wherein R₁, M and U are as defined above.

The invention further relates to a process for the preparation of cyclicforms of BAPO compounds of the formula VII

characterized in that two equivalent of a dimetalated-phosphine R₁P(M)₂are reacted with one equivalent of a tetracarboxylic acid halogenide

to form an intermediate of the formula III″

said intermediate cyclizes and is then oxidized to form phosphine oxidesof the formula VII wherein R₁, M and U′ are as defined above.

Preference is given to using compounds of the formula I or II in which nis 1 and m is 1.

Definitions

C₁–C₁₂alkyl is linear or branched and is, for example, C₁–C₁₂alkyl,C₁–C₈alkyl, C₁–C₆alkyl or C₁–C₄alkyl. Examples are methyl, ethyl,propyl, isopropyl, n-butyl, sec-butyl, isobutyl, tert-butyl, pentyl,hexyl, heptyl, 2,4,4-trimethylpentyl, 2-ethylhexyl, octyl, nonyl, decyl,undecyl, dodecyl. The alkyl groups may be interrupted once or more thanonce by O, S or N(C₁–C₁₂alkyl). If the radicals are interrupted by twoor more O, S or N(C₁–C₁₂alkyl) then the O atoms, S atoms orN(C₁–C₁₂alkyl) groups are in each case separated from one another by atleast one methylene group. The O atoms, S atoms or N(C₁–C₁₂alkyl) groupsare thus not directly consecutive. For example, structural units such as—CH₂—O—CH₃, —CH₂CH₂—O—CH₂CH₃, —[CH₂CH₂O]_(z)—CH₃, where z=1 to 9,—(CH₂CH₂O)₇CH₂CH₃, —CH₂—CH(CH₃)—O—CH₂—CH₂CH₃, —CH₂—CH(CH₃)—O—CH₂—CH₃,—CH₂SCH₃ or —CH₂—N(CH₃)₂ arise.

The alkyl groups may be mono- or polysubstituted by C₁–C₁₂ alkyl; C₁–C₁₂alkoxy, —S—C₁–C₁₂alkyl, phenyl, phenoxy, —COOC₁–C₁₂alkyl,—COO—C₅–C₁₄aryl or CN.

As used herein, the term “C₁–C₁₂alkoxy” refers to a group O—C₁–C₁₂alkyl,wherein the alkyl radical is as described above.

Examples of C₃–C₆cycloalkyl groups are cyclopropyl, cyclobutyl,cyclopentyl, cyclohexyl. The C₃–C₆cycloalkyl groups may be substitutedby C₁–C₁₂ alkyl, C₁–C₁₂ alkoxy, —S—C₁–C₁₂alkyl, phenyl, phenoxy,—COOC₁–C₁₂alkyl, —COO—C₅–C₁₄aryl or CN. Examples are2,4,6-trimethyl-cyclohexyl, 2,6-dimethylcyclohexyl and2,6-dimethoxycyclohexyl.

C₅–C₁₄aryl is phenyl, naphthyl, biphenyl, anthracyl and the like.

The aryl radicals may be mono or polysubstituted by halogen, phenyl,C₁–C₁₂alkyl and/or C₁–C₁₂alkoxy, —S—C₁–C₁₂alkyl, CF₃, Cl,—N(C₁–C₁₂alkyl)₂ or —N(C_(1–C) ₁₂alkyl interrupted by O)₂.

Examples are:

Q is a di-tri or tetravalent arylene residue derived from the followingdi or polycarboxylic acid halogenides, preferably chlorides.Compounds of the Formula A

wherein

-   R is C₁–C₁₂alkyl, C₁–C₁₂alkoxy, C₁–C₁₂alkylthio, C₅–C₁₄aryl,    O—C₅–C₁₄aryl, halogen, NH(C₁–C₁₂alkyl), N(C₁–C₁₂alkyl)₂,    C(O)O(C₁–C₁₂alkyl), CO—NH(C₁–C₁₂alkyl), CO—N(C₁–C₁₂alkyl)₂ or CF₃

Commercial compounds of the formula A are:

-   Phthalic acid and derivatives thereof such as, for example,    tetrafluoro- or tetrachloro phthalic acid, 3-fluorophthalic acid,    4-(trifluoromethyl)phthalic acid, 4-chloro- or 4,5-dichlorophthalic    acid, 4-methylphthalic acid;-   Hemimellitic-, trimellitic- and pyromellitic acid;-   Isophthalic acid and derivatives thereof such as, for example,    tetrafluoroisophthalic acid, 4-bromoisophthalic acid, 4-hydroxy- or    5-hydroxyisophthalic acid, 5-aminoisophthalic acid;-   Trimesic acid, 5-methyl-1,3-benzenedicarboxylic acid;-   Therephthalic acid and derivatives thereof such as, for example,    tetrafluoro- or tetrachloro-terephthalic acid, 2-bromoterephthalic    acid, 2-aminoterephthalic acid, 2,5-dimethyl-terephthalic acid,    2,5-dichloro- or 2,5-dibromoterephthalic acid.    Compounds of the Formula B

wherein R is as defined in formula A.

Commercial compounds of the formula B are 1,4,5,8-naphthalenetetracarboxylic acid or 1,4,5,8-naphthalene tetracarboxylic acidhydrate.

Compounds of the Formula C

wherein R is as defined in formula A.

Commercial compounds of the formula C are 2,3-naphthalenedicarboxylicacid or 1,4-naphthalene dicarboxylic acid.

Compounds of the Formula D

wherein R is as defined in formula A and X is a bond, —O—, —S—,methylene, —CH(CH₃)—, —C(CH₃)₂—, —C(CF₃)₂—, —C(O)—, —S(O)— or —S(O)₂—.

Commercial compounds of the formula D are3,3′,4,4′-benzophenonetetracarboxylic acid, 2,3,2′-biphenyltricarboxylicacid or 4,4′(hexafluoroisopropylidene)phthalic acid.

Compounds of the Formula E

wherein R is as defined in formula A and Y is H₂, O, S or CH₂.

Commercially available is 9-fluorenone-2,7-dicarboxylic acid

Compounds of the Formula F or G

wherein R and Y are as defined above, and W is O, S, CH₂ orN(C₁–C₁₂alkyl).

Commercially available is2,7-di-tert-butyl-9,9-dimethyl-4,5-xanthenedicarboxylic acid.

Compounds of the Formula H, I, J, K, L, M, N or O.

wherein

-   k is 1–3,-   R is as defined above,-   R′ is hydrogen, phenyl, C₁–C₁₂ alkyl or C₃–C₆cycloalkyl,-   A is selected from C₅–C₁₄arylene, C₃–C₆cycloalkylene or    bicycloalkylene, linear or branched C₂–C₂₄alkylene optionally    interrupted once or more than once by non-consecutive —O— or —S—    atoms or by groups selected from —CO—, —COO—, —OCO—, —O—COO—,    phenylene, C₅–C₁₄arylene, C₃–C₆cycloalkylene, —CH═CH—,    bicycloalkylene, biphenylene, —Si(CH₃)₂—, —Si(CH₃)₂—O—Si(CH₃)₂— or    —CF₂—.

The group A may be substituted by C₁–C₁₂alkyl, C₁–C₁₂ alkoxy,—S—C₁–C₁₂alkyl, phenyl, phenoxy, —O—COC₁–C₁₂alkyl, —O—COC₅–C₁₄aryl,—COOC₁–C₁₂alkyl, —COO—C₅–C₁₄aryl, CN, CF₃, F or Cl.

Concerning cyclic forms of BAPO compounds of the formula VI

-   U is a divalent arylene residue derived from the following    dicarboxylic acid halogenides, preferably chlorides, U1–U4

wherein R and X are as defined above.

Concerning cyclic forms of BAPO compounds of the formula VII

-   U′ is a tetravalent arylene residue derived from the following    tetracarboxylic acid halogenides, preferably chlorides, U5 and U6

The Process Starting Compounds:

The preparation of the metalated phosphines R₁P(M)₂ can, for example, becarried out by reacting suitable phosphorus halides R₁P(Hal)₂(preparation of which is known and disclosed, for example, by W. Daviesin J. Chem. Soc. (1935), 462 and J. Chem. Soc. (1944), 276 with thecorresponding alkali metal. Suitable as metal (M) are lithium, sodium orpotassium. Lithium is preferred. The use of mixtures of these metals isalso possible. 4 to 8 molar equivalents of the alkaline metal areadvantageously used. The reaction is advantageously carried out in asolvent. In particular, as solvents, it is possible to use ethers whichare liquid at atmospheric pressure and, room temperature. Examples aredimethyl ether, diethyl ether, methyl propyl ether, 1,2-dimethoxyethane,bis(2-methoxyethyl) ether, dioxane or tetrahydrofuran. Preference isgiven to using tetrahydrofuran. The reaction temperatures areadvantageously −60° C. to +120° C.

Another conceivable method for the preparation of metalated phosphinesis, for example, the reaction of suitable phosphines R₁P(H)₂ with thecorresponding alkali metal hydride or an alkyllithium compound with theexclusion of air in an inert solvent at temperatures of e.g. −80° C. to+120° C. Advantageously, 2 to 4 mol equivalents of the alkali metalhydrides or alkyllithium compound are used. Suitable solvents are e.g.ethers as described above, or inert solvents, such as alkanes,cycloalkanes, or aromatic solvents such as toluene, xylene, mesitylene.

Suitable aryl phosphines can be prepared by reduction of thecorresponding aryldichloro-phosphines [Ar—P—Cl₂], arylphosphonic esters[Ar—P—O(OR′)₂) and arylphosphonous esters [Ar—P(OR′)₂] using LiAlH₄;SiHCl₃; Ph₂SiH₂ (Ph=phenyl): a) LiH, b) H₂O;

a) Li/tetrahydrofuran, b) H₂O or a) Na/toluene, b) H₂O. These methodsare described, for example, in U.S. Pat. No. 6,020,528 (col. 5–6).Hydrogenations using LiAlH₄ are given, for example, in Helv. Chim. Acta1966, No. 96, 842.

The di- or poly carboxylic acid halogenides used as starting materialare known substances, some of which are available. Examples are listedabove.

Carboxylic acid chlorides which are not commercially available may beprepared starting from the corresponding carboxylic acids using knownreactions. The corresponding carboxylic acids may be prepared asfollows.

Compounds H: by reaction of an anhydride with a di-, tri- ortetrafunctional alcohol.

Compound I: by reaction of an anhydride with a di-, tri- ortetrafunctional amine.

Suitable anhydrides are, for example, phthalic anhydride, hemimelliticanhydride, trimellitic anhydride, tetrafluorophthalic anhydride or4,5-dichlorophthalic anhydride.

Compound J: by transesterification of a hydroxy carboxylic acid with adi-, tri- or tetra-functional ester.

Suitable hydroxy carboxylic acids are, for example, 4-hydroxyphthalicacid, 5-hydroxyisophthalic acid, 3-hydroxy- or 4-hydroxybenzoic acid orsalicylic acid.

Compound K: by reaction of an aminocarboxylic acid with a di-, tri- ortetrafunctional acid chloride

Suitable aminocarboxylic acids are, for example, 3-amino- or4-aminophthalic acid, 5-aminoisophthalic acid, 2-aminoterephphthalicacid, antranilic acid, 3-amino- or 4-aminobenzoic acid.

Compounds L, M or N: by reaction of a halogen substituted carboxylicacids with a di-, tri- or tetrafunctional alcohol, amine or thiol

X═O, S, NR′

Suitable halogen substituted carboxylic acids are, for example,3-fluoro- or 4-chlorophthalic acid, 2-fluoroisophthalic acid, 2-fluoro-or 4-fluorobenzoic acid or 4-chlorobenzoic acid.

Compound O: by reaction of a hydroxy carboxylic acid with a di-, tri- ortetrafunctional chloroformiate.

Suitable hydroxy carboxylic acids are, for example, 4-hydroxyphthalicacid, 5-hydroxyisophthalic acid, 3-hydroxy- or 4-hydroxybenzoic acid,salicylic acid.

Cyclic forms of Bapo compounds may be prepared starting from thefollowing dicarboxylic acid chlorides of the formula U1: phthalic acid,tetrafluorophthalic acid, 4,5-dichlorophthalic acid, 4-hydroxy-,3-fluoro- or 4-chloro phthalic acid; of the formula U2 2,2-oxydibenzoicacid or diphenic acid; of the formula U3 naphthalene-1,8-dicarboxylicacid; of the formula U4 2,3-naphthalene dicarboxylic acid; or startingfrom the following tetracarboxylic acids: 3,3′,4,4′-benzophenonetetracarboxylic acid or 4,4′-(hexafluoroisopropylidene)diphthalic acid.

Inventive Process

The process starts by reacting a carboxylic acid halogenide with ametalated phosphine preferably in an inert solvents such as THF, dioxaneor diethylether at a temperature from −20 to 80° C.

An important feature of the process for preparing dimer or multimerforms of BAPO or MAPO compounds comprises the control of the mole ratioof metalated phosphine to di- or poly-carboxylic acid chloride. It isdesirable that about one equivalent of metalated phosphine groups beavailable per equivalent of acid chloride groups. The carboxylic acidchloride is preferably dropped into the phosphine in order to maintainan excess of the phosphine. Using about 0.5 equivalents of metalatedphosphine groups per equivalent of acid chloride groups results incyclic bisacylphosphine oxides.

The reaction between the di- or polycarboxylic acid chloride and themetalated phosphine produces an intermediate having the structuralformula III.

To prepare MAPO compounds the intermediate is treated with an alkyl oraryl halogenide resulting in P-alkylation of the phosphine. Thealkylating agent is added slowly. The reaction is preferably carried outin the same solvent and temperature range as in the first reaction stepproviding the intermediate.

To prepare BAPO compounds the intermediate is treated with anothercarboxylic acid halogenide resulting in P-acylation of the phosphine.The acylating agent is added slowly. The reaction is carried out in thesame solvent and temperature range as in the first reaction stepproviding the intermediate.

The oxidation of the phosphine is carried out using oxidizing agentscustomary in the art. Suitable oxidizing agents are, for example,hydrogen peroxide, air or pure oxygen.

Use

The MAPO and BAPO compounds of the formula I and II as well as thecyclic BAPO compounds of the formula VI or VII can be used asphotoinitiators for the photo-polymerization of ethylenicallyunsaturated compounds or mixtures which comprise such compounds. Thisuse can also take place in combination with other photoinitiators and/orother additives.

Thus, the invention also relates to a photopolymerizable compositioncomprising

-   (a) at least one ethylenically unsaturated photopolymerizable    compound, and-   (b) as photoinitiator, at least one compound of the formula I, II,    VI or VII as defined above.

The unsaturated compounds can contain one or more olefinic double bonds.They can be of low molecular weight (monomeric) or relatively highmolecular weight (oligomeric). Examples of monomers with a double bondare alkyl or hydroxyalkyl acrylates or methacrylates, for example methylacrylate, ethyl acrylate, butyl acrylate, 2-ethylhexyl acrylate or2-hydroxy-ethyl acrylate, isobornyl acrylate, methyl methacrylate orethyl methacrylate. Also of interest are silicon- or fluorine-modifiedresins, e.g. silicone acrylates. Further examples are acrylonitrile,acrylamide, methacrylamide, N-substituted (meth)acrylamides, vinylesters, such as vinyl acetate, vinyl ethers, such as isobutyl vinylether, styrene, alkyl- and halostyrenes, N-vinylpyrrolidone, vinylchloride or vinylidene chloride.

Examples of monomers having two or more double bonds are ethylene glycoldiacrylate, propylene glycol diacrylate, neopentyl glycol diacrylate,hexamethylene glycol diacrylate or bisphenol A diacrylate,4,4′-bis(2-acryloyloxyethoxy)diphenylpropane, trimethylolpropanetriacrylate, pentaerythritol triacrylate or tetraacrylate, vinylacrylate, divinylbenzene, divinyl succinate, diallyl phthalate, triallylphosphate, triallyl isocyanurate or tris(2-acryloylethyl) isocyanurate.

Examples of higher molecular weight (oligomeric) polyunsaturatedcompounds are acrylicized epoxy resins, polyurethanes, polyethers andpolyesters which are acrylicized or contain vinyl ether or epoxy groups.Further examples of unsaturated oligomers are un-saturated polyesterresins which are mostly prepared from maleic acid, phthalic acid and oneor more diols and have molecular weights of from about 500 to 3,000. Inaddition, it is also possible to use vinyl ether monomers and oligomers,and maleate-terminated oligomers having polyester, polyurethane,polyether, polyvinyl ether and epoxy main chains. In particular,combinations of oligomers which carry vinyl ether groups and polymers asdescribed in WO 90/01512 are highly suitable. However, copolymers ofvinyl ether and maleic acid-functionalized monomers are also suitable.Such unsaturated oligomers may also be referred to as prepolymers.

Examples of particularly suitable compounds are esters of ethylenicallyunsaturated carboxylic acids and polyols or polyepoxides, and polymerscontaining ethylenically unsaturated groups in the chain or inside-groups, for example unsaturated polyesters, polyamides andpolyurethanes and copolymers thereof, alkyd resins, polybutadiene andbutadiene copolymers, polyisoprene and isoprene copolymers, polymers andcopolymers containing (meth)acrylic groups in side chains, and mixturesof one or more such polymers.

Examples of unsaturated carboxylic acids are acrylic acid, methacrylicacid, crotonic acid, itaconic acid, cinnamic acid, unsaturated fattyacids such as linolenic acid or oleic acid. Preference is given toacrylic acid and methacrylic acid.

Suitable polyols are aromatic and, in particular, aliphatic andcycloaliphatic polyols. Examples of aromatic polyols are hydroquinone,4,4′-dihydroxydiphenyl, 2,2-di(4-hydroxy-phenyl)propane, and alsonovolaks and resols. Examples of polyepoxides are those based on saidpolyols, particularly aromatic polyols and epichlorohydrins. Inaddition, polymers and copolymers which contain hydroxyl groups in thepolymer chain or in side groups, for example polyvinyl alcohol andcopolymers thereof or hydroxyalkyl polymethacrylates or copolymersthereof, are also suitable as polyols. Further suitable polyols areoligoesters containing hydroxyl end-groups.

Examples of aliphatic and cycloaliphatic polyols are alkylenediolshaving, preferably, 2 to 12 carbon atoms, such as ethylene glycol, 1,2-or 1,3-propanediol, 1,2-, 1,3- or 1,4-butanediol, pentanediol,hexanediol, octanediol, dodecanediol, diethylene glycol, triethyleneglycol, poly-ethylene glycols having molecular weights of, preferably,200 to 1,500, 1,3-cyclopentanediol, 1,2-, 1,3- or 1,4-cyclohexanediol,1,4-dihydroxymethylcyclohexane, glycerol, tris(β-hydroxy-ethyl)amine,trimethylolethane, trimethylolpropane, pentaerythritol,dipentaerythritol and sorbitol.

The polyols may be partially or completely esterified using one ordifferent unsaturated carboxylic acids, where the free hydroxyl groupsin partial esters may be modified, e.g. etherified or esterified withother carboxylic acids.

Examples of esters are: trimethylolpropane triacrylate,trimethylolethane triacrylate, trimethylolpropane trimethacrylate,trimethylolethane trimethacrylate, tetramethylene glycol dimethacrylate,triethylene glycol dimethacrylate, tetraethylene glycol diacrylate,pentaerythritol diacrylate, pentaerythritol triacrylate, pentaerythritoltetraacrylate, dipentaerythritol diacrylate, dipentaerythritoltriacrylate, dipentaerythritol tetraacrylate, dipentaerythritolpentaacrylate, dipentaerythritol hexaacrylate, tripentaerythritoloctaacrylate, pentaerythritol dimethacrylate, pentaerythritoltrimethacrylate, dipentaerythritol dimethacrylate, dipentaerythritoltetramethacrylate, tripentaerythritol octamethacrylate, pentaerythritoldiitaconate, dipentaerythritol trisitaconate, dipentaerythritolpentaitaconate, dipentaerythritol hexaitaconate, ethylene glycoldiacrylate, 1,3-butanediol diacrylate, 1,3-butanediol dimethacrylate,1,4-butanediol diitaconate, sorbitol triacrylate, sorbitoltetraacrylate, pentaerythritol-modified triacrylate, sorbitoltetramethacrylate, sorbitol pentaacrylate, sorbitol hexaacrylate,oligoester acrylates and methacrylates, glycerol di- and triacrylate,1,4-cyclohexane diacrylate, bisacrylates and bismethacrylates ofpolyethylene glycol having molecular weights of from 200 to 1,500, ormixtures thereof.

Also suitable as component (a) are the amides of identical or differentunsaturated carboxylic acids of aromatic, cycloaliphatic and aliphaticpolyamines having, preferably, 2 to 6, particularly 2 to 4, aminogroups. Examples of such polyamines are ethylenediamine, 1,2- or1,3-propylenediamine, 1,2-, 1,3- or 1,4-butylenediamine,1,5-pentylenediamine, 1,6-hexylenediamine, octylenediamine,dodecylenediamine, 1,4-diaminocyclohexane, isophoronediamine,phenylenediamine, bisphenylenediamine, di-β-aminoethyl ether,diethylenetriamine, triethylenetetramine, di(β-aminoethoxy)ethane ordi(β-aminopropoxy)-ethane. Further suitable polyamines are polymers andcopolymers with or without additional amino groups in the side chain andoligoamides containing amino end groups. Examples of such unsaturatedamides are: methylenebisacrylamide, 1,6-hexamethylenebisacrylamide,diethylenetriaminetrismethacrylamide, bis(methacrylamidopropoxy)ethane,β-methacryl-amidoethyl methacrylate,N[(β-hydroxyethoxy)ethyl]acrylamide.

Suitable unsaturated polyesters and polyamides are derived, for example,from maleic acid and diols or diamines. The maleic acid may be replacedby other dicarboxylic acids. They can be used together withethylenically unsaturated comonomers, e.g. styrene. The poly-esters andpolyamides may also be derived from dicarboxylic acids and ethylenicallyunsaturated diols or diamines, particularly from relatively long chaincompounds containing, for example, 6 to 20 carbon atoms. Examples ofpolyurethanes are those constructed from saturated or unsaturateddiisocyanates and unsaturated or saturated diols.

Polybutadiene and polyisoprene and copolymers thereof are known.Suitable comonomers are, for example, olefins, such as ethylene,propene, butene, hexene, (meth)acrylates, acrylonitrile, styrene orvinyl chloride. Polymers containing (meth)acrylate groups in the sidechain are likewise known. These may, for example, be products of thereaction of novolak-based epoxy resins with (meth)acrylic acid, homc- orcopolymers of vinyl alcohol or hydroxy-alkyl derivatives thereof whichhave been esterified using (meth)acrylic acid, or homo- and copolymersof (meth)acrylates which have been esterified usinghydroxyalkyl(meth)acrylates.

The photopolymerizable compounds may be used on their own or in anydesired mixtures. Preference is given to using mixtures of polyol(meth)acrylates.

It is also possible to add binders to the compositions according to theinvention; this is particularly advantageous if the photopolymerizablecompounds are liquid or viscose substances. The amount of binder may,for example, be 5–95% by weight, preferably 10–90% by weight andparticularly 40–90% by weight, based on the total solids. The binder ischosen depending on the field of application and on the propertiesrequired therefore, such as the facility for development in aqueous ororganic solvent systems, adhesion to substrates and sensitivity tooxygen.

Examples of suitable binders are listed in U.S. Patent Publication2001/0031898 which publication is included in the present Application byreference.

Apart from the photoinitiator, the photopolymerizable mixtures can alsocontain various additives such as thermal inhibitors, compounds toincrease the storage stability, light protection agents such as forexample the following light protection agents listed in US PatentPublication 2001/0031898

2-(2′-Hydroxyphenyl)benzotriazoles, 2-hydroxybenzophenones, esters ofunsubstituted or substituted benzoic acids, acrylates, stericallyhindered amines, oxalamides, 2-(2-hydroxy-phenyl)-1,3,5-triazines,phosphites and phosphonites.

The photopolymerizable mixtures can also contain photosensitizers suchas for example the following photosensitizers listed in U.S. PatentPublication 2001/0031898: Triethanolamine, N-methyldiethanolamine, ethylp-dimethylaminobenzoate or Michlers ketone, benzophenone, thioxanthone,in particular also isopropylthioxanthone, anthraquinone and3-acylcoumarin derivatives, terphenyls, styryl ketones, and3-(aroyl-methylene)thiazolines, camphorquinone, but also eosin,rhodamine and erythrosine dyes.

Depending on the intended use, further customary additives are opticalbrighteners, fillers, pigments, both white and coloured pigments, dyes,antistats, wetting agents or levelling auxiliaries.

The choice of additives depends on the field of application in questionand the properties desired for this field. The above-described additivesare customary in the art and are accordingly used in amounts customaryin the art. Concrete examples for possible additives are given in USPatent Publication 2001/0031898

In certain cases, it may be advantageous to use mixtures of two or moreof the photoinitiators according to the invention. It is of course alsopossible to use mixtures with known photoinitiators.

The photopolymerizable compositions advantageously comprise thephotoinitiator in an amount of from 0.05 to 20% by weight, e.g. 0.05 to15% by weight, preferably 0.1 to 5% by weight, based on the composition.The amount of photoinitiator stated is based on the total of all addedphotoinitiators if mixtures thereof are used.

The photopolymerizable compositions can be used for various purposes,for example as printing inks, such as screen printing inks, flexographicprinting inks or offset printing inks, as clearcoats, as colour coats,as white coats, e.g. for wood or metal, as powder coatings, as paints,inter alia for paper, water, metal or plastic, as daylight-curablecoatings for marking buildings and roads, for photographic reproductionprocesses, for holographic recording materials, for image recordingprocesses or for the production of printing plates which can bedeveloped using organic solvents or aqueous-alkaline media, for theproduction of masks for screen printing, as dental filling materials, asadhesives, as pressure-sensitive adhesives, as laminating resins, asphotoresists, e.g. galvanoresists, etch or permanent resists, bothliquid and dry films, as photostructurable dielectrics, and as solderstopping masks for electronic circuits, as resists for the preparationof colour filters for any type of screen or for producing structures inthe production process of plasma displays and electroluminescencedisplays, for the production of optical switches, optical gratings(interference gratings), for the preparation of three-dimensionalobjects by mass curing (UV curing in transparent moulds) or by thestereolithography process, as is described, for example, in U.S. Pat.No. 4,575,330, for the preparation of composite materials (e.g. styrenicpolyesters which may contain glass fibres and/or other fibres and otherauxiliaries) and other thick-layer materials, for the coating or sealingof electronic components or as coatings for optical fibres. Thecompositions are also suitable for the preparation of optical lenses,e.g. contact lenses and Fresnel lenses, and for the preparation ofmedical instruments, auxiliaries or implants.

EXAMPLES

1. Preparation of Dimer Bisacylphosphine Oxide. (BAPO)

[Phenyl-(2,4,6-trimethyl-benzoyl)-phosphinoyl]-{2,4,6-trimethyl-3-[phenyl-(2,4,6-trimethyl-benzoyl)-phosphinoanecarbonyl]-phenyl}-methanone

Formula I, R₁=phenyl, R₂=mesityl, Q=mesitylene, n=1, m=1

120 ml (0.191 mol) buthyllitium were dropped at a temperature of −20° C.to a solution of 10.0 g (0.091 mol) phenylphosphine in 150 mltetrahydrofurane. A Yellow suspension was obtained. Subsequently 11.2 g(0.0455 mol) 2,4,6-trimethylbenzol-1,3-dicarboxylic acid dichloridediluted with 50 ml tetrahydrofurane were added dropwise at a temperatureof 0° C. The reaction mixture was kept at that temperature during 30 minunder stirring. Subsequently 16.6 g (0.091 mol)2,4,6-trimethylbenzoylchloride were added dropwise and stirred at thesame temperature for 2 hours. Subsequently the reaction mixture wasallowed to reach room temperature. The solvent was rotatory evaporated.The residue is taken up in 200 ml toluene. The solution was diluted withwater and the layers were separated. 10.3 g (0.091 mol; 30%) hydrogenperoxide were added to the organic phase. After stirring for 2 h, theorganic phase was washed with water and with aqueous saturated NaHCO₃,dried over MgSO₄ and filtered. Evaporation and Flash columnchromatography (eluent: Hexan/ethylacetat 3:1) gave the title compoundas a yellow viscous resin. ³¹P-NMR 8.30 ppm

¹H-NMR (ppm) 7.72–7.80 (m), 7.45–7.47 (m), 6.76 (s), 6.62–6.67 (m), 2.11(s), 2.05 (s), 1.96 (s) und 1.89–1.92 (d) determined in CDCl₃.

The following BAPOs may be prepared analogously.

Ex Product Educt NMR of the Product 1.a

Phenylphosphine,Phtaloyldichloride,2,4,6-Trimethylbenzoylchloride.³¹P-NMR 13.12 ppm¹H-NMR (ppm) 8.26–8.28 (d), 7.92–7.95(d), 7.57–7.72(m),7.03–7.29 (m), 6.49(s), 2.06 (s), and 1.60(s) in CDCl₃.Smp. 202–203°C. 1.b

Isobutylphosphine,2,4,6-Trimethylbenzol-1,3-dicarboxylicacidchloride,2,4,6-Trimethylbenzoylchloride. ³¹P-NMR 29.45 ppm¹H-NMR(ppm) 6.87(s), 6.77–6.78 (d),1.97–2.20 (m) und0.96–0.98 (t) inCDCl₃. 1.c

Phenylphosphine3,3′,4,4′-benzophenonetetracarboxylicaciddichloride2,4,6-trimethylbenzoylchloride2. Preparation of Dimer Monoacylphosphine Oxide. (MAPO)

[3-(Benzyl-isobutyl-phosphinoanecarbonyl)-2,4,6-trimethyl-phenyl]-(benzyl-isobutyl-phosphinoyl)-methanone

Formula II, R₁=isobutyl, R₃=benzyl, Q=mesitylene, n=1, m=1

120 ml (0.191 mol) buthyllitium were dropped at a temperature of −20° C.to a solution of 8.2 g (0.091 mol) isobutylphosphine in 150 mltetrahydrofurane. Subsequently 11.2 g (0.0455 mol)2,4,6-trimethylbenzol-1,3-dicarboxylic acid dichloride diluted with 50ml tetrahydrofurane were added dropwise at a temperature of 0° C. Thereaction mixture was kept at that temperature during 30 min understirring. Subsequently 15.56 g (0.091 mol) benzylbromide were addeddropwise and stirred at the same temperature for 2 hours. Subsequentlythe reaction mixture was allowed to reach room temperature. The solventwas rotatory evaporated. The residue is taken up in 200 ml toluene. Thesolution was diluted with water and the layers were separated. 10.3 g(0.091 mol; 30%) hydrogen peroxide were added to the organic phase.After stirring for 2 h, the organic phase was washed with water and withaqueous saturated NaHCO₃, dried over MgSO₄ and filtered. Evaporation andFlash column chromatography (eluent: Hexan/Ethylacetat 3:1) gave thetitle compound as a viscous resin. ³¹P-NMR 40.04 ppm

¹H-NMR (ppm) 7.13–7.28 (m), 6.76 (s), 3.14–3.41 (m), 2.01–2.0 (d),1,60–1.97 (m) und 0.89–0.95 (q) determined in CDCl₃.

The following MAPO's may be prepared analogously.

Product Educt

Phenylphosphine2,4,6-Trimethylbenzoylchloriden-Butylbromide

PhenylphosphinePhthaloyldichloriden-Butylbromide

Phenylphosphine3,3′,4,4′benzophenonetetracarboxylicaciddichloriden-Butylbromide3. Preparation of Cyclic Bisacylphosphine Oxide (BAPO)

2-oxo-2-phenyl-2,5-isophosphindole-1,3-dione

Formula VI, R1 is phenyl, U is isophthaloyl.

120 ml (0.191 mol) buthyllitium were dropped at a temperature of −20° C.to a solution of 10.0 g (0.091 mol) phenylphosphine in 150 mltetrahydrofurane. A Yellow suspension was obtained. Subsequently 18.4 g(0.091 mol) of phthalic acid chloride diluted with 50 mltetrahydrofurane were added at a temperature of 0° C. The reactionmixture was stirred at this temperature for 30 minutes and gently warmedup to room temperature with additional stirring for 2 hours. The solventwas evaporated on a rotatory evaporator and the residue diluted with 200ml of toluene and washed with water.

10.3 g (0.091 mol; 30%) hydrogen peroxide was added to the organicphase. After 2 hours at room temperature, the organic phase wasseparated, washed with water and with aqueous saturated NaHCO₃, driedover MgSO₄ and filtered. Evaporation of the solvent and flashchromatography gave the title compound.

Application Example

Weight (g) Product Description 30.0 Ebecryl 605 Epoxyacrylate (UCB) 10.0Ebecryl 7100 Aminoacrylate (UCB) 5.0 Ebecryl 40 PropoxylatedPentaerythrol (UCB) 30.0 OTA 480 Acrylated trifuntional oligomer basedon a glycerol derivative (UCB) 24.0 TPGDA Tripropylene glycol diacrylate0.5 Ebecryl 1360 Silicone hexaacrylate 0.5 Dow Corning 57Siliconeadditive, Dow Corning 100.0 Total OPV Formulation

Photoinitiators were investigated with a concentration of 10% and 8%based on 100% weight of the formulation.

For the determination of the cure speed the formulations were applied towhite card boards (400 μm) and exposed to the UV light of a mediumpressure mercury lamp with a power output of 120 W/cm. The speed of theconveyor belt at which the formulation was completely cured and trackfree, corresponds to the cure speed.

The results are shown in Table 1

TABLE 1 Substrate white cardboard (400 μm) Application equipment(Erichsen) Layer thickness 5 μm Lamps 1 m.p. Hg 120 W/cm (IST) Curespeed (m/min) 10% Photoinitiator 8% Photoinitiator Example 1 90 50Example 1.b 80 10 Example 2 30 15

For the determination of the gloss the formulations were applied to chipboards and cured using the UV light of a medium pressure mercury lampwith a power output of 120 W/cm at a conveyor belt speed of 10 m/min.The gloss of the cured films was measured after the samples werepost-exposed under a lamp of the type TKL 40/05 for 22 hours.

The results are shown in Table 2.

TABLE 2 Substrate chip boards Layer thickness 100 μm Lamps 1 m.p. Hg 120W/cm (IST), TLK 40/05 Cure Speed 10 m/min Equipment gloss: Haze-Gloss(Byk-Gardner) Gloss 20° 10% Photoinitiator 6% Photoinitiator Example 188.00 88.00 Example 1.b 88.00 Example 2 88.00 84.00

1. Process for the preparation of dimer or multimer forms of BAPOcompounds of the formula I,

wherein R₁ is unsubstituted or substituted C₁–C₁₂alkyl, benzyl,C₁–C₁₂alkoxy or C₃–C₈cycloalkyl; R₂ is unsubstituted or substitutedC₃–C₆cycloalkyl or C₅–C₁₄aryl; Q is a di- tri or tetravalent aryleneresidue; n is 1–4, m is 0–2, n+m is 2, 3 or 4, characterized in that(n+m) equivalents of a dimetalated-phosphine R₁P(M)₂ are reacted withone equivalent of a di- or polycarboxylic acid halogenide

to form an intermediate of the formula III

the intermediate III is then reacted with (n+m) equivalents of a furthercarboxylic acid halogenide (R₂—CO-Hal) to form dimer or multimer formsof bisacylphosphine-intermediates of the formula IV

said phosphines IV are then oxidized to form phosphine oxides of theformula I, wherein M is Li, Na or K.
 2. Process according to claim 1,wherein M is Li and wherein the process is carried out in an inertatmosphere at a temperature from −20 to 80° C.